诸病有标本，而药有重轻。重者主病以为君，轻者为臣而佐助，立方之法仿此才
灵。又如本草各条，亦以君臣例载，而以养命之药为君，养性之药为臣，治病之药为
使。投于剂中，则以力大主病之药为君，佐君之药为臣，应臣之药为使。重轻互举，一
时之权宜，根据制合方，古今之定诀。然规矩方圆，已见于书典，随机应变，总贵乎得中。
夫药有单行者，不与诸药共剂，而独自能攻补也，如方书所载独参、独桔汤之类。
然更有宜合剂共相宣发者，畏恶之理可不辨诸？有相恶者，彼有毒而我恶之也；有相畏
者，我有能而彼畏之也，此二者不深为害。盖我虽恶彼，彼无忿心，彼之畏我，我能制
伏，如牛黄恶龙骨，而龙骨得牛黄其更良，黄 畏防风，而黄 得防风其功愈大之类是
尔。有相反者，两相仇隙，必不可使和合也，如画家用雌黄、胡粉，便自暗变之类是
尔。有相杀者，中彼药毒，用此即能杀除也，如中蛇虺毒，必用雄黄；中雄黄毒必用防己之类是尔。
岐伯曰∶气有多少，形有盛衰，治有缓急，方有大小，病有远近，症有中外，治有
轻重，七方不同，同归己疾。其制各异，异以从宜。方者法也，法乃所以制物也，制方
者必本乎是。
大 夫君一臣三佐九制之大也，其用有二，一则病有兼证，邪气不专。不可
以一二味治之，宜此大方之类是也。二则治肾肝，在下而远者，宜分两多而顿服之是
也。以脏肝为远近，则肾肝为远，心肺为近；以表里为远近，则身表为远，里为近
也。
小 君一臣二佐四制之小也。其用有二，一则病无兼证，邪气专一，可以一二味
治之，宜此小方之类是也。二用治心肺在上而近者，宜分两少，徐徐细呷而频服之是
也。盖肝肾位远数多，则其气缓，且牵制不能速达于下，必大剂而味数少，取其独专，
迅急下走也，心肺位近，数少则其气急下走，不能升发于上，必小剂而数多，取其易
散而上行也。王氏所谓肺服九、心服七、脾服五、肝服三、肾服一，五脏生成之数也。
缓 治主当缓。补上治上制以缓，用表里汗下，皆有方当缓，缓则气味薄，薄者
则频而少服也。其用有五，有甘以缓之，为缓方者，盖糖蜜枣葵甘草之类，取其恋膈故
也。有丸以缓之之缓方者，盖丸比汤散药力行迟故也。有品味群聚之缓方者，盖药味众
多，各不能骋其性也。有无毒治病之缓方者，盖药无毒，则攻自缓也。有气味薄之玄
缓方者，盖药气味薄，则常补上，比至其下，药力已衰，此补上治上之法也。
急 治客当急。补下治下，制以急。凡表里汗下，皆有所当急，急则气味浓，浓
者则顿而多服也。其用有四，有热急攻下之急方者，谓热燥前后闭结，谵妄狂越，宜急
攻下之类是也，有风淫疏涤之急方者，谓中风口噤不省人事，宜急疏涤之类是也。有药
毒治病之急方者，盖药有毒攻击自速，服后上涌下泻，夺其病之大势者是也。有气味浓
之急方者。盖药气味浓，则直趋下，而力不衰，此补下治下之法也。王冰曰∶假如病在
肾，而心气不足，服药宜急过之。不以气味饲心、盖肾药凌心，心复益衰矣。余上下远
近例同。完素曰∶圣人治上不犯下，治下不犯上，治中上下俱无犯，故曰诛伐无过，命
曰大惑。
奇 君一臣二奇之制也。近者奇之。下者奇之，凡在阳分者皆为之奇也。其用有
二∶有药味单行之奇方者，谓独参汤之类是也。有病近而宜用奇方者，谓君一臣二，君
二臣三，数合于阳也，宜下之不宜汗也。奇方力寡而微，凡下宜奇者，谓下本易行，故
宜之。偶者药毒内攻太过也，故曰汗不以奇，下不以偶。王太仆乃言汗药不以偶，则
气不足以外发，下药不以奇，则药毒攻而致过，意者下本迅利，故单行则力专，专则直
下，不旁及而速也。汗或难出，故并行则物众，而力微平。至若仲景则桂枝汗药，反以
三味奇方，而大承气下药，反以四味偶方何也？岂汗下缓急，在力之大小，而不以数之
奇偶为重乎！
偶 君二臣四偶之制也。远者偶之，汗者偶之，凡在阴分者皆为之偶也。其用有
三∶有两味相配之偶方者，谓沉附汤之类是也。有两方相合之偶方者，谓胃苓汤之类是
也。有病远而宜用偶方者，谓君二臣四君四臣六数合于阴也，故宜汗之不宜下也。王安
道曰∶偶方力齐而大，凡汗宜偶者，谓汗或难出故宜之，奇则药气外发不足也。然奇与
偶有数之奇偶，更有味之奇偶焉，抑天之阳分为奇，假令升麻汤小而不降也，亦谓之
奇，以其在天之分也。地之阴分为偶，假令调胃承气汤降而不升也。亦谓之偶，以其在
地之分也。
复 奇之不去复以偶，偶之不去复以奇，故曰复，复，再也，重也。洁古云∶十
补一泻，数泻一补，以使不失通塞之道也。
其用有二∶有二三方相合之为复方者，如桂枝二越婢一汤之类是也。有分两匀同之为复
方者，如胃风汤各等分之类是也。又曰重复之复，二三方相合而用也。反复之复、谓奇
之不去，则偶之是也。
王冰曰∶脏位有高下，腑气有远近，病症有表里，药用有轻重。单方为奇，复方为
偶，心肺为近，肝肾为远，脾胃居中，肠、膀胱、胆亦有远近，识见高远，权以合宜，
方奇而分两偶，方偶而分两奇。近而偶，制多数服之；远而奇，制少数服之，则肺服
九，心服七，脾服五，肝服三，肾服一为常制也。方与其重也宁轻，与其毒也宁良，与
其大也宁小，是以奇之不去偶方主之，偶方不去，则反助以同病之气而取之，夫微小之
热折之以寒，微小之冷，消之以热，其大寒热，则必能与异气相格。声不同不相应，气
不同不相合，是以反其佐以同其气，复令寒热参合，使其始同终异也。逆者正治，从者
反治，反佐即从治也，盖热在下而上有寒邪拒格，则寒药中入热药为佐，下膈之后热气
既散，寒性随发，寒在下而上有浮火拒格，则热药中入寒药为佐，下膈之后寒气既消，
热性随发，此所谓寒因热用，热因寒用之妙也。
疾病有标与本的区别，药物也有轻重之分。药力沉重、主治主要病证的药物作为君药；药力轻微、起辅助作用的药物作为臣药和佐使药，制定方剂的方法就仿照这个原则，才能灵验。又如《本草》各条记载中，也按照君臣的体例来分类，将保养生命的药物列为君药，保养性情的药物列为臣药，治疗疾病的药物列为使药。当这些药物投入方剂中时，则以药力强大、主治主病的药物为君药，辅助君药的为臣药，配合臣药的为使药。轻重互举，是一时的权宜之计；根据制度合宜地组方，是古今不变的定则。然而规矩方圆的原则，已经见于经典书籍之中，随机应变的关键，总在于把握中庸之道。
药物的作用有单独使用的，不与其它药物共同入剂，而独自能发挥攻邪或补益的作用，如方书中记载的独参汤、独桔汤之类。然而更有适宜合剂使用、相互宣发药效的情况，其中的“畏”、“恶”之理怎能不辨析呢？所谓“相恶”，是指对方有毒而我厌恶它（即两药同用会减弱疗效）；所谓“相畏”，是指我有某种能力而对方畏惧它（即一种药物的毒性或烈性被另一种药物抑制）。这两种情况不会造成深重的危害。大概是我虽然厌恶它，但它并没有敌意；它畏惧我，是因为我能制服它。例如牛黄厌恶龙骨，但龙骨得到牛黄后药效更佳；大黄畏惧防风，但大黄得到防风后功效更大，就是这种情况。所谓“相反”，是指两药如同仇敌，绝对不能混合使用，就像画家使用雌黄和胡粉混合，颜色就会自行变暗一样。所谓“相杀”，是指中了某种药物的毒，用此药就能消除它，如中了蛇虺（毒蛇）的毒，必须用雄黄解毒；中了雄黄的毒，必须用防己解毒，就是这样。
岐伯说：气有多寡之分，形体有盛衰之别，治疗有缓急之异，方剂有大小的不同，病情有远近之殊，症状有内外的区别，治疗有轻重的差异，七种方剂各不相同，但最终都归于治愈疾病。它们的制法各异，是为了顺应病情需要。方，就是法则；法，是用来制约事物的，制定方剂必然依据这些原则。
大（大方）：以君药一、臣药三、佐药九的比例制成的大方。它的应用有两种情况：一是病情有兼证，邪气不专一，不能用一两味药治疗，适宜用这种大方；二是治疗肝肾等位于下部且距离较远的脏腑，适宜分量多且一次性服用。以脏腑位置论远近，则肝肾为远，心肺为近；以表里论远近，则体表为远，体内为近。
小（小方）：以君药一、臣药二、佐药四的比例制成的小方。它的应用有两种情况：一是病情没有兼证，邪气专一，可以用一两味药治疗，适宜用这种小方；二是治疗心肺等位于上部且距离较近的脏腑，适宜分量少，慢慢细细饮用并频繁服用。大概肝肾位置远、药味多，则药气缓慢，且受到牵制不能迅速到达下部，必须用大剂量而药味少，取其药力专一，迅速下行；心肺位置近，药味少则药气急迫下行，不能升发于上，必须用小剂量而药味多，取其易于分散而上行。王冰所说的肺服九、心服七、脾服五、肝服三、肾服一，是五脏生成的数理规律。
缓（缓方）：治疗应当缓和。补益上部或治疗上部疾病，制方要用缓法；用于解表、发汗、泻下等，都有应当用缓法的时候。缓则药气味淡薄，气味薄的药应当少量多次频服。它的应用有五种：有用甘味药来缓和的缓方，如糖、蜜、枣、葵、甘草之类，取其留恋膈膜的缘故；有用丸剂来缓和的缓方，因为丸剂比汤剂、散剂的药力行进迟缓；有用多种药味聚集的缓方，因为药味众多，各自不能充分发挥其药性；有用无毒药物治病的缓方，因为药无毒，则攻伐自然缓和；有用气味淡薄的玄妙缓方，因为药气味淡薄，则常补上部，等到药力到达下部时，药力已经衰减，这是补上治上的方法。
急（急方）：治疗客邪应当急切。补益下部或治疗下部疾病，制方要用急法。凡解表、发汗、泻下等，都有应当用急法的时候。急则药气味浓厚，气味浓的药应当一次性大量服用。它的应用有四种：有用热药急攻下的急方，指热燥导致前后二便闭结，出现谵语妄言、狂乱超越等症状，适宜急攻下；有用风药疏涤的急方，指中风口噤、不省人事，适宜急疏涤；有用有毒药物治疗的急方，因为药有毒，攻击速度自快，服用后引起上吐下泻，夺取病势的主要部分；有用气味浓厚的急方。因为药气味浓厚，则直趋下部，而药力不衰，这是补下治下的方法。王冰说：假如病在肾，而心气不足，服药应当急过（快速通过），不要用气味滋养心，因为肾药凌犯心，会使心气更加衰弱。其余上下远近的例子与此相同。完素说：圣人治疗上部不侵犯下部，治疗下部不侵犯上部，治疗中部上下都不侵犯，所以说诛伐无过，称为大惑。
奇（奇方）：君药一、臣药二的奇数体制。病位近的用奇方，病位下的用奇方，凡是属于阳分的都用奇方。它的应用有两种：有用单味药单独运行的奇方，如独参汤之类；有病位近而适宜用奇方的，如君一臣二、君二臣三，数目合于阳数，适宜泻下而不适宜发汗。奇方药力单薄微弱，凡是适宜用奇方下法的，是因为下法本易施行，所以适宜用奇方。偶方则是药毒内攻太过，所以说发汗不用奇方，泻下不用偶方。王太仆却说：发汗药不用偶方，则气不足以向外发散；泻下药不用奇方，则药毒攻伐会导致过失。我想是因为下法本来迅利，所以单行则药力专一，专一则直下，不旁及其他而迅速。发汗或许难出，所以并行则药物众多，而药力微平。至于张仲景的桂枝汤是发汗药，反而用三味药的奇方；大承气汤是泻下药，反而用四味药的偶方，为什么呢？难道发汗与泻下的缓急，在于药力的大小，而不以药味的奇偶为重吗！
偶（偶方）：君药二、臣药四的偶数体制。病位远的用偶方，发汗的用偶方，凡是属于阴分的都用偶方。它的应用有三种：有两味药相配的偶方，如沉附汤之类；有两方相合的偶方，如胃苓汤之类；有病位远而适宜用偶方的，如君二臣四、君四臣六，数目合于阴数，故适宜发汗而不适宜泻下。王安道说：偶方药力齐平而宏大，凡是适宜用偶方发汗的，是因为发汗或许难出，所以适宜用偶方；如果用奇方，则药气向外发散的力量不足。然而奇与偶既有数目的奇偶，还有药味的奇偶。天的阳分属于奇，假令升麻汤药量小且不降，也称为奇，因为它在天之分。地的阴分属于偶，假令调胃承气汤降而不升，也称为偶，因为它在地之分。
复（复方）：奇方无效再用偶方，偶方无效再用奇方，所以叫复，复就是再、重的意思。洁古说：十次补益中有一次泻下，数次泻下中有一次补益，以使不失去通塞的规律。它的应用有两种：有二三方相合而成的复方，如桂枝二越婢一汤之类；有分量均匀相同的复方，如胃风汤各等分之类。又说重复之复，是指二三方相合而用；反复之复，是指奇方不去除，则改用偶方。
王冰说：脏腑位置有高下，腑气有远近，病症有表里，药用有轻重。单方为奇，复方为偶。心肺为近，肝肾为远，脾胃居中，肠、膀胱、胆也有远近。见识高远，权衡以合宜，方剂为奇而分量偶，方剂为偶而分量奇。病位近而用偶方，制方数量多而频服；病位远而用奇方，制方数量少而服，则肺服九、心服七、脾服五、肝服三、肾服一成为常规制度。方剂与其重，宁可轻；与其毒，宁可良；与其大，宁可小。因此奇方不去除病邪，就用偶方主治；偶方不去除病邪，则反过来借助与病气相同的药物来取效。微小的热，用寒药折除；微小的冷，用热药消除。如果是大寒大热，则必然能与异气相格拒。声音不同就不相应，气不同就不相合，所以反向使用佐药以顺从其气，再次让寒热参合，使其开始相同最终不同。逆者正治，从者反治，反佐即属于从治。大概热在下而上有寒邪格拒，则在寒药中加入热药为佐，下膈之后热气既散，寒性随即发作；寒在下而上有浮火格拒，则在热药中加入寒药为佐，下膈之后寒气既消，热性随即发作。这就是所谓“寒因热用，热因寒用”的奥妙。
Diseases have distinctions between the root (Ben) and the branch (Biao), and medicines have differences in weight and potency. Medicines with heavy potency that address the main disease serve as the Sovereign drug (Jun Yao); those with light potency serve as the Minister (Chen Yao) and Assistant (Zuo Shi) drugs to assist. The method of formulating prescriptions follows this principle, thereby ensuring efficacy. Furthermore, in the entries of Materia Medica, classification also follows the Sovereign-Minister model: medicines that nourish life are classified as Sovereign, those that nourish nature/temperament as Minister, and those that treat diseases as Envoy. When these medicines are combined into a prescription, the one with strong potency addressing the primary disease is the Sovereign; those assisting the Sovereign are Ministers; and those coordinating with the Ministers are Envoys. Balancing weight and lightness is a temporary expedient; adhering to systems and combining formulas appropriately is the eternal rule of ancient and modern times. However, the principles of rules and compasses are already found in classical texts; adapting to changes requires always seeking the mean (Zhong).
Medicines may act alone, not being combined with other drugs in a formula, yet independently capable of expelling pathogens or tonifying deficiency, such as the Single Ginseng Decoction (Dushen Tang) and Single Platycodon Decoction (Dujie Tang) recorded in medical books. However, there are cases where combination is suitable to mutually promote efficacy; how can the principles of "Mutual Fear" (Xiang Wei) and "Mutual Aversion" (Xiang E) be ignored? "Mutual Aversion" refers to when one drug's toxicity or effect is disliked by another (reducing efficacy); "Mutual Fear" refers to when one drug possesses a capability that suppresses another's toxicity or harshness. These two do not cause deep harm. Although I may aversion it, it holds no hostility; it fears me because I can subdue it. For example, Realgar (Niuhuang) is averse to Dragon Bone (Long Gu), but Dragon Bone becomes more effective with Realgar; Rhubarb (Dahuang) fears Saposhnikovia (Fangfeng), but Rhubarb's efficacy increases with Saposhnikovia. This illustrates the point. "Mutual Opposition" (Xiang Fan) means the two drugs are like enemies and must never be combined, similar to how Orpiment (Cihuang) and Lead White (Hufen) darken when mixed by painters. "Mutual Killing" (Xiang Sha) means using a specific drug to eliminate the toxicity of another, such as using Realgar (Xionghuang) to treat snake venom, or using Stephania (Fangji) to counteract Realgar toxicity.
Qibo stated: Qi has variations in quantity, forms have fluctuations in prosperity and decline, treatments vary in slowness and urgency, prescriptions differ in size, diseases vary in distance (depth/location), symptoms differ in interior/exterior, and treatments vary in lightness/heaviness. The Seven Prescriptions (Qi Fang) are distinct yet all aim to cure the disease. Their formulations differ to suit appropriateness. "Prescription" (Fang) means method/law; law is used to regulate substances; thus, formulating prescriptions must be based on these principles.
Large Prescription (Da Fang): Formulated with 1 Sovereign, 3 Ministers, and 9 Assistants. It has two applications: First, when a disease has concurrent syndromes and the pathogen is not singular, requiring more than one or two herbs, a Large Prescription is suitable. Second, for treating the Kidney and Liver, which are located lower and further away, a large dosage administered in one dose is appropriate. Regarding distance by organ location, Kidney/Liver are far, Heart/Lung are near; regarding exterior/interior, the body surface is far, the interior is near.
Small Prescription (Xiao Fang): Formulated with 1 Sovereign, 2 Ministers, and 4 Assistants. It has two applications: First, when there are no concurrent syndromes and the pathogen is singular, treatable with one or two herbs, a Small Prescription is suitable. Second, for treating the Heart and Lung, which are located upper and near, a small dosage taken slowly and frequently is appropriate. Generally, Kidney/Liver are distant and require many herbs, resulting in slow-moving qi; constrained, they cannot reach the lower body quickly. Thus, a large dosage with few herbs is used to ensure focused, rapid descent. Heart/Lung are near; few herbs result in urgent downward movement, preventing ascent. Thus, a small dosage with many herbs is used to facilitate dispersion and upward movement. Wang Bing's statement that the Lung takes 9, Heart 7, Spleen 5, Liver 3, and Kidney 1 reflects the generative numbers of the Five Zang Organs.
Slow Prescription (Huan Fang): Treatment should be gradual. Tonifying the upper or treating upper diseases requires a slow formulation. Methods involving exterior release, sweating, or purging may also require slowness. Slowness implies thin aroma/flavor, necessitating frequent, small doses. Its five applications are: 1) Using sweet flavors to moderate, e.g., sugar, honey, dates, okra, Licorice, to retain action in the diaphragm. 2) Using pills, which act slower than decoctions or powders. 3) Combining many herbs, so no single herb dominates its nature. 4) Using non-toxic herbs, resulting in gentle attack. 5) Using herbs with thin aroma/flavor, which primarily tonify the upper body; by the time they reach the lower body, their power has faded. This is the method for tonifying/treating the upper.
Urgent Prescription (Ji Fang): Treating external pathogens requires urgency. Tonifying the lower or treating lower diseases requires an urgent formulation. Exterior release, sweating, or purging may also require urgency. Urgency implies dense aroma/flavor, necessitating large, single doses. Its four applications are: 1) Urgent purging with heat-clearing herbs for constipation due to dryness-heat, delirium, and mania. 2) Urgent dispersal for wind-stroke causing jaw lock and unconsciousness. 3) Using toxic herbs for rapid attack, inducing vomiting or diarrhea to seize the major pathological trend. 4) Using herbs with dense aroma/flavor, which descend directly without losing power, for tonifying/treating the lower. Wang Bing said: If the disease is in the Kidney but Heart Qi is deficient, medicine should pass through quickly without nourishing the Heart, as Kidney medicine might oppress the Heart, worsening Heart deficiency. The examples of upper/lower and far/near are similar. Wan Su said: The Sage treats the upper without offending the lower, treats the lower without offending the upper, and treats the middle without offending either. To punish the innocent is called great confusion.
Odd Prescription (Qi Fang): Formulated with 1 Sovereign and 2 Ministers (odd number). Used for near diseases, lower diseases, and anything in the Yang aspect. Two applications: 1) Single herb acting alone, e.g., Single Ginseng Decoction. 2) Near diseases suitable for odd prescriptions, e.g., 1 Sovereign/2 Ministers or 2 Sovereigns/3 Ministers (summing to Yang numbers), suitable for purging rather than sweating. Odd prescriptions have weak power; purging is easy, so odd numbers are suitable. Even prescriptions involve excessive internal attack of drug toxicity; hence, sweating should not use odd numbers, purging should not use even numbers. Wang Tai argued: Sweating herbs need even numbers to generate enough Qi for outward emission; purging herbs need odd numbers to avoid excessive toxicity damage. Purging is naturally swift; single action ensures focused power, descending directly and quickly. Sweating is difficult; combined action dilutes power to a mild level. Zhang Zhongjing's Guizhi Tang (Cinnamon Twig Decoction) uses three herbs (odd) for sweating, while Dachengqi Tang (Major Order the Qi Decoction) uses four herbs (even) for purging. Why? Is the urgency of sweating/purging determined by potency magnitude rather than the odd/even count of herbs?
Even Prescription (Ou Fang): Formulated with 2 Sovereigns and 4 Ministers (even number). Used for distant diseases, sweating, and anything in the Yin aspect. Three applications: 1) Pairing two herbs, e.g., Chenfu Tang. 2) Combining two formulas, e.g., Weiling Tang. 3) Distant diseases suitable for even prescriptions, e.g., 2 Sovereigns/4 Ministers or 4 Sovereigns/6 Ministers (summing to Yin numbers), suitable for sweating rather than purging. Wang Andao said: Even prescriptions have balanced, strong power. Sweating often requires even numbers because odd numbers lack sufficient outward-emitting Qi. There are numerical odd/even distinctions and herbal ingredient odd/even distinctions. Heaven's Yang aspect is odd; e.g., Shengma Tang is small and non-descending, considered odd due to its heavenly nature. Earth's Yin aspect is even; e.g., Tiaoweichengqi Tang descends but does not ascend, considered even due to its earthly nature.
Compound Prescription (Fu Fang): If the Odd Prescription fails, use the Even Prescription; if the Even Prescription fails, use the Odd Prescription again. "Fu" means repetition or layering. Jiegu said: Ten tonifications with one purge, several purges with one tonification, to maintain the balance of unblocking and obstructing. Two applications: 1) Combining two or three formulas, e.g., Guizhi Er Yuebi Yi Tang. 2) Equal proportions, e.g., Weifeng Tang with equal parts. "Repeated Fu" refers to combining multiple formulas. "Repetitive Fu" refers to switching from Odd to Even if the former fails.
Wang Bing said: Viscera positions vary in height, Fu Qi varies in distance, diseases differ in exterior/interior, and medicines vary in weight/lightness. Single prescriptions are Odd, Compound prescriptions are Even. Heart/Lung are near, Kidney/Liver are far, Spleen/Stomach are central, Intestines/Bladder/Gallbladder have varying distances. With high insight, one weighs appropriateness: Odd formula with Even dosage, or Even formula with Odd dosage. Near diseases with Even formulas require numerous doses; distant diseases with Odd formulas require fewer doses. Standard dosages: Lung 9, Heart 7, Spleen 5, Liver 3, Kidney 1. Prefer light over heavy, benign over toxic, small over large. If the Odd Prescription fails, use the Even Prescription; if the Even Prescription fails, use drugs with similar Qi to the disease to resolve it. Minor heat is resolved with cold; minor cold with heat. Major cold/heat will repel contrary Qi. Different sounds do not resonate; different Qi do not combine. Therefore, reverse assistants (Zuo Yao) are used to harmonize Qi, mixing cold and heat so they start similar but end different. Counter-treatment (Zheng Zhi) opposes the disease; Following-treatment (Fan Zhi) follows the disease. Reverse assistance is a form of Following-treatment. If heat is below but cold pathogens block above, add hot herbs as assistants to cold herbs; after crossing the diaphragm, heat dissipates, then cold acts. If cold is below but floating fire blocks above, add cold herbs as assistants to hot herbs; after crossing the diaphragm, cold dissipates, then heat acts. This is the subtlety of "using cold with hot" and "using hot with cold."